Injection molding is a commonly used process in which molten material is injected into a cavity, or mold, to form a desired part of a specific shape. Injection molding is used to create many different types of parts used in automotive, computer, household, or other applications.
One type of injection molding process also includes the forming of a part made of both metal and a type of plastic, where the plastic is in a molten form and injected into a mold containing the portion of the part made of metal. The plastic forms in an overmold around the metal material into the desired shape. The finished part is therefore made of both plastic and metal.
Additionally, parts made of more than one piece of metal, such as sheet metal, are often connected together through the use of what is referred to as “clinching.” Sheet metal clinching involves the connection of two pieces of metal without additional components, and an interlock is formed between the two sheets. This type of connection is also referred to as a “Tog-L-Loc™” process, which is a trademark for a process used by BTM Corporation of Marysville, Mich.
When parts made of plastic and multiple pieces of metal are created using both clinching and injection molding, there are two different stages of the manufacturing process used. One stage is the connection, or clinching, of the metal pieces. Another stage includes the placement of the connected metal pieces into a mold, and injecting a molten material around the metal pieces such that the desired portion of the finished part which is made of plastic is formed properly around the two pieces of metal.
However, using these two stages to form the desired part is costly. Accordingly, there exists a need for an improved method of manufacturing a part made of plastic and metal, which reduces the steps required in the manufacturing process.